Episode 146 of "Malcolm in the Middle"
s07e17 Hal's Dentist
Title: Hal's Dentist
Original Air Date: 03/26/2006 on Fox
Plot Outline:
Hal's friend Trey tells him to come to his dental office when he looses a tooth during a poker game, but their friendship becomes in jeopardy when Hal's faced with a $2,000 bill and causes a fight between them. Reese, meanwhile, teaches Lois how to ride a bike, while Malcolm and Dewey find sleeping as their new favorite pastime.
